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Old 26th Jul 2009, 17:02
  #3921 (permalink)  
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HarryMann;

Yes, you would be correct in that statement - warmer air, fewer molecules. If the air suddenly warms up, until things stabilize, Mach decreases, (speed of sound decreases, so relative to that, aircraft Mach decreases), engine power is reduced, low-speed buffet onset speed increases.

But I would offer that in and of itself, such a change, (while rare) would not cause loss of control. Engine thrust would increase immediately as per design and as you say, the mass would take some moments to increase velocity. In taking a look on the Jepp CR2, a 20C temperature change makes about a 15 to 20kt change in TAS, (the Jepp assumes "steady state" of course so a sudden "rise" in OAT shows a 20kt increase in TAS but in fact, until things stabilize at the new "equation", there would be an airspeed deficit), and pitch attitude would decrease very slightly first as "CRZ ALT" mode is a "soft" altitude with a 100' window to wander 50' up and 50' down to correct minor speed variations without changing engine thrust.

BOAC;
A 17C increase in OAT under the conditions AF447 was in wouldn't make a dramatic difference in and of itself. The airplane was a long way from the so-called coffin corner everyone is on about. I haven't seen any data to the contrary, proving otherwise. Here's the chart you're referring to, I think. Below this one, here is a graph of the environmental envelope for a 330, (no center tanks):

The following caveat/caution will be familiar to most in aviation. It applies to all readers and is necessary to ensure clear understanding as to intent and use:
The following information is for education, demonstration and discussion only and is not valid for flight planning. These graphs are not associated with any specific airline or model of A330. Do not use these graphs for planning or flight operations purposes.

ISA vs Altitude, M0.80 & M0.82 Cruise:






Here is a buffet boundary graph for an A330:

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Old 26th Jul 2009, 17:10
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PJ - thanks for all those graphs - the one I recall put it closer to the line, but did not specify the margin. I have spent some time looking back for this graph (posted pre 3/Jul) but I think it got 'moderated'out of existence. Yours certainly closes the case for 'too high'.
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Old 26th Jul 2009, 17:20
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investigation rigged?

What evidence is there to support a conclusion that this ship bellyflopped whole into the Atlantic? The autopsies don't support this; right?
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Old 26th Jul 2009, 17:47
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Automation pulling the rug from under the pilot's feet

...before the fault detection schemes switch it off (A/THR & A/P).

Beyond the A/THR chasing declining airspeeds and reducing the upper aerodynamic margin before being switched off, could it be that the A330 alpha protection laws had also reduced the plane's AoA reacting to the same declining airspeeds ? An Airbus in approach (AP off, A/THR on in managed speed) with substained high surface winds was surprised by a sudden wind drop (-20 kts in a few sec on the airspeed) and began to sink, the pilot tried to abort the approach/landing and to initiate a go-around but the AoA laws prevented it (reacting to the airspeed drop), by inducing a nose down that the pilot could not overrule. What about a button on the stick for the pilots to overule any automation, primary reflexes of the A330, protection laws included ? full authority (like on Airbuses operating flight tests at the limits of the envelope ?)
Jeff

Last edited by Hyperveloce; 26th Jul 2009 at 18:15.
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Old 26th Jul 2009, 18:24
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Jeff;
An Airbus in approach (AP off, A/THR on in managed speed) with substained high surface winds was surprised by a sudden wind drop (-20 kts in a few sec on the airspeed) and began to sink, the pilot tried to abort the approach/landing and to initiate a go-around but the AoA laws prevented it, by inducing a nose down that the pilot could not overrule.
Hm, can you provide a link to the report or to the quote, Jeff? On the surface of it, this doesn't sound correct so I wouldn't mind verifying what happened just out of curiosity, thanks.
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Old 26th Jul 2009, 18:39
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PJ2, you are right, I am mixing up two cases:
- the Cayenne incident (A340 A/THR increasing thrust reacting to a wind drop):
http://www.bea-fr.org/docspa/2001/f-...f-zc010525.pdf
- the interrupted go-around (A320 AoA laws reacting to turbulence and updrafts):
http://www.pn.ewi.tudelft.nl/educati.../notes/loc.pdf
so I was wrong in saying that the AoA protection law was triggered by declining airspeeds (due to a wind drop) in this case, this was the result of up/down wind gusts.
Jeff
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Old 26th Jul 2009, 18:40
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At the risk of setting off some very personalized feelings, can someone with some specific knowledge confirm something that continues to come up in the circles in which I find myself.

There is a rather large international operator of Airbus aircraft whose very experienced instructor cadre are absolutely convinced that the pilot on board this aircraft was also on board the aircraft that landed and skidded off the runway at Toronto in 2005.

Can anyone confirm this or is this just another one of the "I'll-bet-I-know" rumors that get started? I reaffirm, this one organization is apparently absolutely sure of their position.
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Old 26th Jul 2009, 18:46
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It IS odd that while we've seen details of the experience on the A330 and on this stretch of the Atlantic of AF447's crew, I've seen no names published.
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Old 26th Jul 2009, 19:14
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Thanks Jeff, that makes sense.
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Old 26th Jul 2009, 19:19
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Originally Posted by AirRabbit
There is a rather large international operator of Airbus aircraft whose very experienced instructor cadre are absolutely convinced that the pilot on board this aircraft was also on board the aircraft that landed and skidded off the runway at Toronto in 2005.
Even if it was true, what would it prove ?
It was an A340 that skidded off the runway in 2005 and we can read in the BEA report that Marc (the AF 447 captain) qualified to fly A340 in 2007: "Qualification de type Airbus A340 obtenue le 9 août 2007" (p. 15). Hence it was not the AF 447 captain. The 37 yrs old AF 447 copilot whose name is not known was certified on A340 in 2002 (he had many more flights on A330/A340 than the CPT) but he is obviously not the F-GLZQ captain who had first flown on his own on a glider on the 1st dec. 1963 (Toronto report), nor the F-GLZQ copilot who joined Air France in 1985 (should also be well over 40 yrs in 2009)
Jeff
sources:
Le Bureau de la sécurité des transports du Canada - RAPPORTS AVIATION - 2005 - A05H0002
http://www.bea.aero/docspa/2009/f-cp...cp090601e1.pdf

Last edited by Hyperveloce; 26th Jul 2009 at 20:20.
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Old 26th Jul 2009, 20:06
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Nice sleuthing work Jeff. Such work should have been done by the "very experienced instructor cadre [who] are absolutely convinced".
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Old 26th Jul 2009, 20:09
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I think the co-pilot of the Toronto plane was a women, and she was PF during that landing. All three pilots in AF447 were males.
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Old 26th Jul 2009, 20:22
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You might want to recall that it was the F/O of the Toronto accident aircraft in 2005 who was at the controls initially - and, if the accident information is correct, that would make the Toronto F/O a male, not female. The Canadian's don't release the names of pilots involved in accidents they are investigating. If the AF447 Captain (Marc, leaving last name blank) was first type rated on the A330 in October 2006 and type rated on the A340 in August 2007 - does anyone know what his assignment was in 2005?

I'm not making accusations ... I'm asking for anyone who may KNOW the facts.

Last edited by AirRabbit; 26th Jul 2009 at 20:40.
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Old 26th Jul 2009, 20:24
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air france toronto incident

The Transport Safety Board report indicates that the flight deck crew were all male. Transportation Safety Board of Canada - AVIATION REPORTS - 2005 - A05H0002
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Old 26th Jul 2009, 20:29
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I am sorry. I checked the facts, and the female co-pilot was on a plane during an incident in french Guyana. I mixed-up the two incidences.
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Old 26th Jul 2009, 20:40
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Originally Posted by AirRabbit
You might want to recall that it was the F/O of the Toronto accident aircraft in 2005 who was at the controls initially - and, if the information is correct, that would make the Toronto F/O a male, not female. I'm not making accusations ... I'm asking for anyone who may KNOW the facts.
I read in the Toronto report:
"Le commandant de bord a été désigné pilote aux commandes (PF) pour le décollage et la première moitié du vol. Le copilote devait être le PF pendant la seconde moitié du vol, y compris pendant l'approche et l'atterrissage à CYYZ. Les tâches de PF/PNF (pilote non aux commandes) avaient été interverties afin de permettre au commandant de bord d'effectuer un décollage au cours de ce vol. Les tâches ont été échangées à 16 h 17, et l'équipage est passé du pilote automatique no 1 au pilote automatique no 2."
(the CPT was the PF who took off the plane and flew the 1st half of the flight, the copilot being scheduled to be the PF for the 2nd half, approach and landing)
"À 16 h 17, les membres d'équipage ont échangé leurs tâches de PF et de PNF, ce qui s'est traduit par un passage du pilote automatique no 1 au pilote automatique no 2. À partir de ce moment-là, c'est le copilote qui a été le PF"
(at 16:17, the copilot becomes the PF and he is the one who will land the plane at 20:01)
source: Le Bureau de la sécurité des transports du Canada - RAPPORTS AVIATION - 2005 - A05H0002

...and the Toronto copilot joined AF in 1985 (over 40 yrs in 2009): he is not the AF 447 captain (not qualified for A340 in 2005) nor the copilots (too young). So the facts seem to oppose to the possibility that either the Toronto CPT (now probably retired) or the copilot/PF for landing may have been in the AF 447 cockpit, don't you agree ?
Jeff
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Old 26th Jul 2009, 20:51
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Hyperveloce, Brazil said several days ago it has identified 49 of the 50 bodies recovered. Was the matching of recovered bodies to assigned seats against 33 bodies, or some higher number? (As I recall, at least three of the bodies recovered are those of the crew.)

And without being specific to individuals, is wes wall's characterization correct that the recovered bodies came from all sections of the aircraft, with somewhat more bodies from the right side than the left?
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Old 26th Jul 2009, 21:16
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SaturnV, it appears to me that the distribution of colored seats is much more dense at the rear of the plane. There are indeed colored seats in every parts of the plane, but how to be sure that all colored seats were occupied at the impact ?

Last edited by Hyperveloce; 26th Jul 2009 at 21:27.
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Old 26th Jul 2009, 21:28
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Originally Posted by Hyperveloce
...and the Toronto copilot joined AF in 1985 (over 40 yrs in 2009): he is not the AF 447 captain (not qualified for A340 in 2005) nor the copilots (too young). So the facts seem to oppose to the possibility that either the Toronto CPT (now probably retired) or the copilot/PF for landing may have been in the AF 447 cockpit, don't you agree ?
I'm afraid you have the advange of me, Jeff, as I don't read French very well. However, if you say that the pilot of AF447 was not assigned to and did not fly the A340 as a copilot in 2005 - I agree with your conclusion. But if the Toronto copilot joined Air France some 24 years ago and the AF447 pilot was rated in the A330 in 2006 and rated in the A340 in 2007, these facts do not indicate any reason why they cannot apply to a single person. Certainly, the AF447 pilot was flying something for Air France in 2005, but I don't know what - and, as I understand the reports, the AF447 captain was younger than his copilot(s) on that flight. Is this not true?

I'm only interested because of the absolute certainty with which I am told these two pilots are one in the same and, if true (notice, I said IF true) that would speak volumes about whether or not Air France takes seriously the fact that their pilots operate with a really good sense of situational awareness regarding things like weather.
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Old 26th Jul 2009, 21:49
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The AF 447 CPT was 58 in 2009 (I think close to the retirement), and not qualified for A340 in 2005. The 37 yrs AF 447 copilot could have flown an A340 in 2005 but the ages do not match: the Toronto copilot joined AF in 1985 (and followed a pilot training course in th U.S. the following year). Let's assume he had at least 18 yrs in 1985, it would give at least 18+(2009-1985)=42 yrs in 2009, which exceeds the ages (32 and 37 yrs) of bth the AF 447 copilots. The Toronto CPT would be over 60 in 2009. Jeff
PS) next time this rumor will come up again in the circles in which you find yourself, kill it if you agree with the above.

Last edited by Hyperveloce; 26th Jul 2009 at 22:14.
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